Implement DPI for perspective bitmaps in PDF - we save the bitmap at the resolution requested.

R=reed@google.com, vandebo@chromium.org

Review URL: https://codereview.chromium.org/54913004

git-svn-id: http://skia.googlecode.com/svn/trunk@12230 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed